Sean S. Mahase, MD

Radiation Oncologist, Medical Director #Education Vice Chair @PennStHershey l #RadOnc #btsm #pedonc #srs #oligomets #spine l 🏋️🧘🏻‍♂️🎨📘 l 💭= opinions

[Advances, an ASTRO Journal @Advances_ASTRO]

📌 Impact of Radionecrosis and Local Recurrence on Overall Survival After Stereotactic Radiosurgery for Brain Metastases 🧠

🔗 https://t.co/zLFWzoaKKY
@ASTRO_org @EJVaios @PeterFecci
@MuzamilArshad18

🔹1383 pts
🔸 large, multi-institutional cohort
🔹 Patients diagnosed with LR were diagnosed sooner after SRS than RN (5.8 vs 8.3 months)
🔸 Local recurrence was associated with significantly worse OS than radionecrosis (15.2 vs 40.4 months)
🔹 Patients symptomatic from either LR or RN presented earlier after SRS than asymptomatic patients and had worse OS
🔸 On binomial logistic regression, RN was associated with single fraction SRS (odds ratio [OR] = 0.38, P = 0.012), receipt of immunotherapy after SRS (OR = 0.32, P < 0.014), and a longer interval from SRS (OR = 0.94, P = 0.028).

[Samuel Chao @SamuelChaoMD]

I am glad these studies are forthcoming. @DanTrifMD providing very thoughtful comments and review @ISRSy Congress #ISRS2026. Dan is helping to lead some of these studies.

[Penn State Radiation Oncology @PSH_CocoaBeams]

Please join us in welcoming @LeilaTchelebi to Penn State Radiation Oncology! We’re excited to have Dr. Tchelebi join the department and look forward to the experience and care she will bring to our patients and team.

[PDBrown @PDBrownOnc]

🚨🚨 ASCO 2026 Final Results Randomized trial resected brain met Brachytherapy vs Post-Op SRS🚨
- Incredible Surg Bed Control with Brachy (↑↑OS as well)
- Surg bed recurrence 12% SRS vs 1% GammaTile

[Rohit Malde @roxboxfix]

Adjuvant radiotherapy versus observation following curative surgery for early-stage oral squamous cell carcinoma (AREST tria) ASCO 2026

[International Consortium on Meningiomas (ICOM) @ICOMeningioma]

The integration of #DNAMethylation and Copy Number Variation-profiles into the IntS unified risk score offer an enhanced prognostic differentiation of #Meningioma patients - this was the finding from a recent study published in @JNeurooncol.

Read here: https://t.co/fSOrJpLgLB

[Jeff Ryckman @jryckman3]

So, who is going to develop free software to overlay RT DICOM onto follow-up CT imaging after radiotherapy, thereby decreasing patient scanxiety by correlating prior radiotherapy fields w/ diagnostic imaging?

Because this paper shows why it matters.🧵👇

@uwradonc @UWRadiology

[Zain Siddiqui @ZainSiddiquiMD]

Celebrating @FSamaan match with colleagues @SSMahaseMD , @MitchMachtay and medical students. Looking forward to seeing Fadi's bright future ahead helping cancer patients. @MayoFL_RORes @ARRO_org

[Penn State Radiation Oncology @PSH_CocoaBeams]

Congratulations to @FSamaan on taking the next step toward a career in Radiation Oncology (Matched to Mayo Clinic Florida)! We also welcomed students interested in becoming Radiation Oncologists to learn more about the field.

[Advances, an ASTRO Journal @Advances_ASTRO]

What are the outcomes associated w/ re-irradiation for meningiomas?

This systematic review and meta-analysis identified 16 studies with 385 pts who received re-☢️ for meningioma.
🔘 Median time from initial RT: 38 mo
🔘 Re-☢️ techniques used: SRS (43%), FSRT (21%), particle therapy (28%)
🔘 Pooled rate of Local Control: 53% (95% CI 48-58%)
🔘 Pooled rate of Overall Survival: 73% (95% CI 67-78%)
🔘 Pooled rate of Symptomatic RT Necrosis: 8% (95% CI 5-11%)
🔘 Pooled rate of Acute Toxicity: 22% (95% CI 17-28%)
🔘 Pooled rate of Chronic Toxicity: 16% (95% CI 11-21%)

🔗 - https://t.co/dDR8zllxu6
@ASTRO_org #radonc #bcsm

[ASTRO @ASTRO_org]

New in #practicalRO: Stereotactic Body Radiation Therapy for Non-Spine Bone Metastases: A Case-Based Radiosurgery Society Review. #radonc https://t.co/hv2T4Nbvpx

[ASTRO @ASTRO_org]

New in #practicalRO: Practical Guidelines for Spinal SBRT Post-Treatment Follow-Up: Empirical Consensus from Quebec Oncology Centers. #radonc https://t.co/tqQVfj3iph

[Stanislav (Stas) Lazarev, MD @StasLazarev]

@SuyogCancer @OncBrothers Until proper ph. 3 RCT showing at least non-inferiority of vorasidenib vs SOC in terms of survival or QoL, this $500K/yr drug with ORR of 11% and 2yr LF of 40% should not be used in any setting. Ever. Period.

[PDBrown @PDBrownOnc]

Randomized Trial 1 Yr Seizure prophylaxis after glioma surgery
1 Yr Seizure 47% levetiracetam vs 41% no prophylaxis
1 Yr OS 59% levetiracetam vs 69% no prophylaxis
No proven role seizure prophylaxis in glioma
https://t.co/PUFitBxUYU

[arjun sahgal @SahgalArjun]

The entire @Sunnybrook spine #SBRT team has come together to share 17 years of research and clinical observations in this review for @NatRevClinOncol. We are a true multidisciplinary team that have had a singular focus to develop the technique and evidence https://t.co/IHALJ97ZCa

[PDBrown @PDBrownOnc]

Radiotherapy Review in NEJM:

“Underuse and refusal of indicated radiotherapy have been shown to increase cancer-specific mortality and the risk of death in both curative and palliative settings”

https://t.co/AVKnIbrw6M

[Samuel Chao @SamuelChaoMD]

Proud to be part of the ARS Appropriate Use committee for CNS. This committee ask important questions relevant to how we look after patients. Currently led by @MichaelTMilano and soon to be led by @joshuapalmermd. @EricLehrer will give an update @ArsRocket Annual Meeting ‘26.

[Jason Sheehan @jasonpsheehan]

Just out in Plos One from my team. The multicenter study shows an expanding role for SRS in the management of hemangioblastoma patients.

[PDBrown @PDBrownOnc]

Meta-analysis Post-Op SRS resected brain met
1 Yr Surgical Bed Control 80% SRS vs. 87% fSRS
No diff LC Margin/No Margin
No diff LC SRS &lt; or &gt; 30 days since resection
Await results A071801
https://t.co/3g4FZF90gp

[Elisabetta Bonzano MD, PhD @to_be_elizabeth]

📌 Top 10 Tips for Stereotactic Body Radiation Therapy Contouring and Planning in Oligometastatic Disease: Lessons Learned From the UK SBRT QA Program ☢️
🔗 https://t.co/WkZDZSoA4I @OncoAlert #OncoAlertAF @IJROBP @fifimcdrmh @royalmarsdenNHS 
🔹Standardize definitions.
🔸 Optimize use of supporting imaging.
🔹 Motion management.
🔸 Optimize patient preparation.
🔹 Use all available TPS tools to optimize contouring.
🔸 Check auto-contouring output.
🔹 Appropriate use of OAR dose-volume constraints.
🔸 Maximize PTV coverage.
🔹 Conform tightly to the PTV.
🔸 Managing multiple lesions.